Large power generators are monitored to detect health conditions of the generator to identify failures that may need to be remedied before the condition causes damage to the generator that may require considerable downtime to repair. For example, a generator part having an abnormally high temperature may be indicative of an incipient failure of the part. Thermocouples mounted at strategic locations on the generator have been used to monitor certain parts of the generator to detect abnormal temperatures. For example, generator stator bars may be cooled by internal channels conducting cooled pressurized hydrogen or water therethrough. Failures in a bar may be detected by monitoring a temperature differential of the pressurized hydrogen or water entering and exiting a channel, such as by disposing a thermocouple at the inlet and outlet of the channel.
Monitoring conditions of such generators may be complicated by the need to enclose the cooled generator within gas tight hermetic enclosures, such as in the case of hydrogen cooled generators. Complex particulate sensors, such as generator condition monitors (GCM) available from Environment One Corporation, mounted outside generator enclosures have been used to extract gas samples from within the enclosure to detect particulates within the gas indicative of a generator component experiencing abnormally high heating. For applications on air cooled generators, such systems typically include blower, vacuum pumps, switching valves, humidification system water supplies and filtering system and tend to be expensive and difficult to maintain.